Railway traffic controlling apparatus



Feb. 4, 1958 F. T. PASCOE RAILWAY TRAFFIC CONTROLLING APPARATUS Filed NOV. 28, 1952 INVENTOR. FPQIZIi Z Pascoe.

HIS

BY U) m ATTORNEY mv m 5+ Sm n 1 hr IL" M Hul 2- p SEN United States Patent RAILWAY TRAFFIC CONTROLLING APPARATUS Frank T. Pascoe, Scott Township, Allegheny County, Pa.,

assignor to Westinghouse Air Brake Company, Wilmerding, Pro, a corporation of Pennsylvania ApplictttiomNovemberZS, 195 2,Serial*No; 323,049 1 9 Claims. (Cl. 24633) order to save on the cost of maintenance, as well as on the cost of original installation, it may beconsidered preferable to provide apparatus, for controlling railway trafiic governing means for a switching area, which does not require the use of track circuits or other traflic responsive or detecting means within the switching area.

Furthermore, steel ties might be used for one or more tracks in some switching areas, and in such cases track circuits within the switching area would not be satisfactory.

An object of my invention is therefore the provision of apparatus for controllingtrafiic governing means to authorize only one switcher to work over any given switching area at any given time.

Another object of my invention is the provision of apparatus for controlling treflic governing means for a stretch of track which is notequipped with track circuits or other trafiic responsivemeans.

A feature of my invention for accomplishing these objects is the provision of trafiic governing means such, for example, as a signal of any suitable type, adjacent each point of entrance for a stretch of track such, for example, as a switching area for governing the movements of railway vehicles onto the stretch of track.

Another feature of my invention is the provision of suitable traffic responsive means such, for example, as

two track circuits, one in advance of, and the other in the rear of, the traffic governing means adjacent each point of entrance for a stretch of track such, for example, as a switching area.

Still another feature of my invention is the provision of means controlled by such traflic responsive means in response to a vehicle approaching in the rear of the traffic governing means for any given point of entrance to a given stretch of track for placing the corresponding traific governing means in condition to direct the vehicle to enter the stretch of track only if there is no other vehicle on the stretch of track.

Still another feature of my invention is the provision of means controlled by said traffic responsive means, in response to a first vehicle passing the trafiic governing means for any given point of entrance to a given stretch of track, for placing the corresponding traflic governing means in condition to stop another vehicle while the given stretch of track is occupied by the first vehicle.

Yet another feature of my invention is the provision of means controlled by the trafiic responsive means in response to a vehicle leaving the given stretch of track for'preparing the traflic governing means for directing another vehicle to" enter-the given stretch of track in response to the approach of said another vehicle.

My invention, as indicated by the foregoing paragraphs concerning'its'objects'and features, relates-to railway traffic controllingapparatus for controlling traflic governingmeans'such, for example, as signals of any suitable type .for governing-the-movement of vehicles such, for "example, asswitchers-onto a given-stretch of track such; forexarnple} as a switching area, which is not equipped with track circuits or'other traflic responsive means; and comprises-ftrafiic responsive means such, for example, as two'track'circuits for each exit point, and also two track circ'uits;one'-inthe'rear of; and theother in advance of, thetraiiidgoverning; means adjacent each point 'of entrancefor the 'givenstretch of track; trafiic control means-such, forexamplq'as'a traffic control relay for each exit point for the given stretch of track, each of which is controlled by' tlie traflic responsive means tobecome energizedonly when'a vehicle leaves the given stretch cf'track atthe corresponding exit point, and each "of which'theriremains energized until the vehido and all thecars, if 'any which it may be pulling, have passed the trafiio" responsive means adjacent the correspondingexit point; master control'means such, for example, as a master" control relay controlled by the traffic responsive means and'by the trafiic control relays to become energizedwhen'the vehicle and any cars which it may be pulling leave-the switching area, and to then remain energized until a vehicle approaching the given stretch cf trackpassesdhe-trafiicgoverning means-at an entrancepoint; and means controlled by the traffic re sponsive means for'each entrance point and each exit point, and bythe traffic controlmeans' and 'master control means, for controlling the-traffic governing means for each entrance point to authorize'a'vehicle'toenter the given stretch of track only if it isnot' already occupied by another vehicle.

I shall describe" one-form of apparatusembodying my invention, and shall thenpoint out the novel features thereof in claims. 7

The accompanying drawing constitutes a diagrammatic view showing one form-of appuatusembodying my invention for a switching area which isnot-equipped with track circuits or'other'traiiic responsive means; saidapparatus including two track-circuits adjacent each of'the entrance and exit points, which are designatedby the reference characters a and b,'for'the switching area; including a signal, designated by the reference character 18 or 28, adjacent the adjoining ends of the track circuits for each entrance point-a or b, respectively; including a repeater relay, ,designatedby the reference character .1- IATPR or Z-ZATPR, 'for'use if the point a or b, respectively, servesas an exit point, each of these repeater. relays controlled by' front contacts ofthe track relays for the corresponding exit point; including a trafiic control relay, designatedby the reference character lXSR. or ZXSR, for each exit point a or b,respectively; each controlled by the repeaterrelay for the corresponding-exit point and by the track relay for'the first; track circuit shunted bya switcher leaving the switching area-at the correspondingexit point; including a master control relay, designated by the reference, character=ENSR,- controlled by the traffic control relays and by the first track circuit shunted: by a switcher: leaving the switching area at any exit point; and: including signal relays, designated by the reference characterslI-IR- andxZHR, eachof which is controlled by the trackaelays-and by. the trafiic control relays and master control relayggforacontrolling: signals 15 and 25, respectively.-

Similar referencewcharactersz refer to similar par-ts, :in the drawing.

A switching area is shown in the drawing, having limit points a and b, and comprising a main track, designated by the reference character MT, a first storage track, designated by the reference character 181, and a second storage track, designated by the reference character 2ST. As shown in the drawing, each of the points a and b serves at times as an entrance point, and at other times also serves as an exit point. However. point a, for example, could be used for only an entrance point, and point b could be used as an exit point only, and there could be other points serving only as entrance points and others serving only as exit points, and also other points which could serve as both an entrance and an; exit point, as shown for points a and b.

I shall assume that trafiic movements toward the right, as shown in the drawing, are in the eastbound direction,

whereas traffic movements toward the left, as shown in the drawing, are in the westbound direction.

In order to simplify the drawing. each track, comprising two parallel series of track rails, is represented by a single line.

Adjacent, and to the west of point a. track MT is divided by insulated joints 3 into a first section. designated by the reference character lAT. and a second section. designated by the reference character lT. Adjacent. and to the east of point b, track MT is divided by insulated joints 3 into a first section. designated by the reference character 2AT, and a second section. designated by the reference character 2T. Each of the track sections is provided with a track circuit including a suitable source of current, such as a battery 4. connected across the rails adjacent one end of the section. and a track relay. designated bv the reference character R. preceded by the reference character for the corresponding section, connected across the rails adjacent the opposite end of the section A signal. designated by the reference character 18. is located adjacent the adjoining ends of sections 1AT and IT for governing switchers entering the switching area in an east ound direction at oint a. A second signal. designated bv the reference character 28. is located adjacent the adioining ends of sections ZAT and 2'! for governing switchers entering the switching area in the westbound direction at point b. The signals may be of any suitable design such. for example, as the well-known color light type which has yellow and red light units, designated by the reference characters Y and R, respectively, as shown in the drawing.

Each of the relays l-lATPR and 2-2ATPR is shown as being of a slow releasing type, to provide a longer closed pickup circuit period for relays lXSR and 2XSR, respectively. However, it would not be necessary for relays I-IATPR and 2-2ATPR to be slow releasing, if relays lXSR and 2XSR were quick enough to pickup, or if the voltage of the source of current for energizing these relavs were high enough. 7 The control circuits and the signal lighting circuits may be supplied with energy from any suitable source such, for example, as a battery Q, having terminals B and N. as shown in the drawing.

Having described, in general, the arrangement and control of the various parts of one form of apparatus embodying my invention, I shall now describe the circuits and operation in detail.

As shown in the drawing, each of the track sections is unoccupied, and therefore each of the track relays is energized; each of the signal relays ll-IR and 2HR is deenergized, and therefore each of the signals 18 and 28, respectively, is displaying the red or stop indication; relays l-lATPR, 2-2ATPR and ENSR are energized; and relays IXSR and 2XSR are deenergized.

The circuit by which relay l-lATPR is energized passes from terminal B, through the front point of contact S of relay 1TR, contact 6 of relay IATR, and the winding of relay l-lATPR to terminal N. Relay 2 ZATPR is energized by a similar circuit, controlled by relays ZTR and ZATR.

Relay ENSR is energized by its stick circuit, passing from terminal B, through contacts 13 and 14 of relays lTR and 2TR, respectively, contact 15 of relay ENSR, and the winding of relay ENSR to terminal N.

Lamp R of signal 15 is lighted by an obvious circuit passing from terminal B, through the back point of contact 29 of relay lHR, and lamp R to terminal N. Lamp R of signal 25 is lighted by a similar circuit, which includes the back point of contact 30 of relay 2l-IR.

I shall assume that a first switcher approaches signal 15, preparatory to entering the switching area ab at point a.

When the switcher enters section lAT, deenergizing relay lATR, contact 6 of relay IATR opens the circuit traced for relay l-lATPR, causing relay l-lATPR to be deenergized. Such operation of relay 1-1ATPR at this time, however, performs no useful function.

Relay lATR, upon becoming deenergized, completes a pickup circuit for relay IHR, this circuit passing from terminal B, through contacts 13 and 14 of relays 1TR and 2TR, respectively, contacts 18, 19 and 20 of relays 2XSR, ENSR and lXSR, respectively, contact 21 of relay IATR, contact 22 of relay 2I-IR, contact 23 of relay 2ATR, and the winding of relay lHR to terminal N. Relay lHR, upon becoming energized, completes its stick circuit, which is the same as its pickup circuit just traced except that it includes contact 24 of relay ll-IR instead of contact 23 of relay ZATR. Relay lHR, upon thus becoming energized, opens its contact 29 at the back point, thereby extinguishing lamp R of signal 18, and then closes its contact 29 at the front point, thereby completing a circuit passing from terminal B, through the front point of contact 29 of relay IHR, and lamp Y of signal 18 to terminal N, for lighting lamp Y of signal 18.

When the switcher enters section IT in response to the lighting of lamp Y of signal 15, relay lTR will become deenergized, so that its contact 13 will open the pickup and stick circuits, just described, for relay IHR, causing relay lHR to again become deenergized. With relay II-IR again deenergized, lamp Y of signal 18 will be extinguished, and lamp R of this signal will again be lighted. When relay lTR becomes deenergized, its contact 13 also opens the stick circuit traced for relay ENSR, causing relay ENSR to also become deenergized.

When the switcher leaves section lAT, relay lATR becomes energized, thereby opening its contact 21 in the circuit previously described for relay 1HR. When the switcher leaves section IT and is on the switching area, contact 13 of relay 1TR becomes closed in the pickup and stick circuits traced for relay lHR, but relay lHR remains deenergized because contact 19 of relay ENSR and contact 21 of relay lATR are open.

I shall next assume that a second switcher approaches signal 13, preparatory to entering the switching area a-b at point a. When the second switcher enters section lAT, deenergizing relay 1ATR, contact 21 of relay IATR becomes closed in the circuits described for relay 1HR, but relay 1HR remains deenergized because contact 19 of relay ENSR is still open. Signal 15 will therefore continue to display the stop indication, and will prevent the second switcher from entering the switching area while it is occupied by the first switcher.

I shall now assume that the first switcher leaves the switching area 'a-b at point b. When the first switcher enters section 2T while leaving area a--b, contact 9 of relay 2TR becomes opened at its front point, thereby deenergizing relay 2-2ATPR. If relay 2XSR were quick enough acting, or if the voltage of the source Q were sufiiciently high, relay 2XSR would close its front contacts during the brief period while contact 11 of relay 2-2ATPR is still closed at its front point after contact 9 of relay ZTR becomes closed at its back point, even if relay 2-2ATPR were not of a slow releasing type; However, in order to provide a longer period during which the pickup circuit for relay ZXSR is closed, relay z'2-"2ATPR, in the particular form of apparatus shown in theaccompanying drawing, is of the slow release type.

The pickup circuit by which relay 2XSR becomes energized passes from terminal B, through the back point of contact 9 of relay 2TR, the front point of contact 11 of relay 2-2ATPR, and the winding of relay ZXSR to terminal N. Relay ZXSR, upon becoming energized, completes a first stick circuit which is the same as the pickup circuit just traced except that it includes contact 12 of relay ZXSR instead of the front point of contact 11 of relay 2-2ATPR. Relay 22ATPR, upon releasing its contact 11, completes a second stick circuit for relay ZXSR, this circuit passing from terminal B, through the back point of contact 11 of relay 2-2ATPR, contact 12 of relay ZXSR, and the winding of relay ZXSR to terminal N.

When the first switcher enters section ZAT, contact of relay ZATR will become opened in the circuit for relay 22ATPR, which is however already deenergized on account of contact 9 of relay 2TR being open at the front point. Relay ZATR, upon becoming deenergized, closes its contact 25 in the circuits for relay ZHR, which are, however, already open at contact 19 of relay ENSR and contact 18 of relay 2XSR.

When the first switcher leaves section 2T, so that relay 2TR is again energized, relay ENSR becomes energized by a pickup circuit passing from terminal B, through contacts 13 and 14 of relays 1TR and ZTR, respectively, contact 16 of relay ZXSR, and the Winding of relay ENSR to terminal N. Relay ENSR, upon thus becoming energized, again completes its stick circuit previously traced.

While relay ZATR is still deenergized on account of the switcher being on section ZAT, relay 2XSR is still energized by its second stick circuit, and therefore contact 18 of relay ZXSR is open in the circuits for relay ZHR. Relay ZHR therefore still remains deenergized.

When the first switcher leaves section 2AT, contact 25 of relay ZATR becomes opened in the circuits for relay ZHR. Relay ZATR, upon becoming energized, completes, at its contact 10, thecircuit for energizing relay 2-2ATPR which, upon becoming energized, opens the stick circuit traced for relay ZXSR, causing relay 2XSR to be deenergized.

With contact 18 of relay ZXSR new again closed, and with contact 21 of relay lATR closed on account of the second switcher occupying section lAT, relay lHR will again become energized by its pickup and stick circuits previously described. Yellow lamp Y of signal 18 will now again become lighted, and therefore the second switcher can enter the switching area at point a. The operation of the apparatus in response to the second switcher entering the switching area will then be as previously described for the first switcher.

I shall now assume that the second switcher leaves the switching area at point a instead of at point b. When the second switcher enters section 1T while leaving the switching area at point a, deenergizing relay ITR, relay lXSR will become energized by its pickup and stick circuits similarly to the manner in which relay ZXSR became energized in response to the first switcher leaving the switching area at point b.

When the second switcher now enters section 1AT, contact 21 of relay lATR will become closed in the circuits for relay 1HR, which will, however, be open at contact 19 of relay ENSR and at contact 20 of relay lXSR.

When the second switcher leaves section 1T, relay ENSR will become energized by a second pickup circuit which is the same as the first pickup circuit traced for this relay except that it includes contact 17 of relay IXSR instead of contact 16 of relay 2XSR.

Also, when the second switcher leaves section 1T, relay 1-1ATPR will still be deenergized on account of relay IATR being deenergized, and therefore relay lXSR will still be retained in theen'ergi-zed condition *by itssecond stick-circuit. With reIay IXSR-thusenergized, its con tact 20 will be open, so that neither relay ll-IR nor relay 2HR can become energized.

When thesecond switcherleaves section lAT, contact 21 of relay lATR will become opened'in-the circuits for relay *lHR. Relay -11ATPR' will nowbecome energized because of the closing of contact 6013 relay IATR. Relay llXSR will therefore become-deenergized, and all parts of'the apparatus will then'again be in the normal condition in which they are shown in the drawing.

1 have described the operation of the apparatus shown in the accompanying drawing when switchers enter the given switching area a--b*in theeastbound direction and then leave in either theeastbound or the westbound direction. It is believed that; in view'of'suchdescription, the operation of the apparatus when a switcher enters in the westbound direction at point b. can be readily traced from the accompanying drawing.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of'the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway traific controlling apparatus for controlling movements of railway vehicles onto a given stretch of track which is not equipped with traffic responsive means, comprising in combination, traflic governing means located adjacent each entrance point for said given stretch of track for governing trafiic movements onto the given stretch of track at the corresponding entrance point, first trafiic responsive means located. in the rear of the traffic governing means for each of 'said entrance points, second traffic responsive means located in advance of the traffic governing means for each of said entrance points, means controlled by the said first traffic responsive means in response to a first vehicle approachingin the rear of the traflic governing means for any corresponding entrance point for placing the corresponding traflic governing means in condition to direct the said first vehicle to enter the said given stretch of track, means controlled by the said second trafiic responsive means in response to said first vehicle passing the corresponding trafiic governing means for placing'all of said traffic governing means in condition to stop a second vehicle, and directional means controlled by both the trafiic responsive means for any entrance point in response to said first vehicle leaving said given stretch of track at the corresponding entrance point for preparing the trafiic governing means for all of the entrance points for directing a second vehicle to enter said given stretch of track at any entrance point in response to control of the first trafiic responsive means at the corresponding entrance point by said second vehicle.

2. Railway trafiic controlling apparatus for controlling movements of railway vehicles onto a given stretch of track which is not equipped with'trafiic responsive means, comprising in combination, traffic governing means located adjacent each entrance point for said given stretch of track for governing traffic movements onto the given stretch of track at the corresponding entrance point, first trafiic responsive means located in the rear of the trafiic governing means for each of said entrance points, second traflic responsive means located in advance of the trafiic governing means for each of said entrance points, means controlled by the said first trafiic responsive'means in response to a first vehicle approaching in the rear of the traffic governing means for any corresponding entrance point for placing the corresponding traffic governing means in condition to direct the said first vehicle to enter the said given stretch of track, means controlled by the said second traffic responsive means in response to said first vehicle passing the corresponding traffic governing means for placing all of said tratfic governing meansrin Condition to stop a second vehicle, traffic responsive means located adjacent each exit point for said given stretch of track, and means controlled by the traflic responsive means for any of said exit points in response to said first vehicle leaving said given stretch of track at the corresponding exit point for preparing the traific governing means for each entrance point for directing a second vehicle to enter said given stretch of track at any entrance point in response to control of the first trafiic responsive means at the corresponding entrance point by said second vehicle.

3. Railway traffic controlling apparatus for controlling movements of railway vehicles onto a given stretch of track which is not equipped with trafiic responsive means, comprising in combination, trafiic governing means located adjacent each entrance point for said given stretch of track for governing traffic movements onto the given stretch of track at the corresponding entrance point, first tratfic responsive means located in the rear of the trafiic governing means for each of said entrance points, second trafiic responsive means located in advance of the trafiic governing means for each of said entrance points, a circuit closed by the said first trafiic responsive means for any entrance point in response to a first vehicle approaching in the rear of the tratfic governing means for the corresponding entrance point for placing the corresponding trafiic governing means in condition to direct the said first vehicle to enter the said given stretch of track, means controlled by the said second trafiic responsive means in response to said first vehicle passing the corresponding trafiic governing means for opening said circuit for placing all of said traffic governing means in condition to stop a second vehicle, and directional means controlled by both the trafiic responsive means for any entrance point in response to said first vehicle leaving said given stretch of track at the corresponding entrance point for preparing the trafl'ic governing means for each entrance point for directing a second vehicle to enter said given stretch of track at any entrance point in response to control of the first traific responsive means at the correspondingentrance point by said second vehicle. to

4. Railway traflic controlling apparatus for controlling movements of railway vehicles onto a given stretch of track which is not equipped with traffic responsive means, comprising in combination, tratfic governing means located adjacent each entrance point for said given stretch of track for governing traific movements onto the given stretch of track at the corresponding entrance point, first trafiic responsive means located in the rear of the traffic governing means for each of said entrance points, second trafiic responsive means located in advance of the traflic governing means for each of said entrance points; a circuit closed by the said first traific responsive means for any entrance point'in response to a first vehicle approach ing in the rear of thetraffic governing means for the corresponding entrance point for placing the corresponding traflic governing means in condition to direct the said first vehicle to enter the said given stretch of track, a master control relay which is normally energized but which becomes deenergized by the second trafiic responsive means for any entrance point iii-response to said first vehicle entering said given stretch of track at the corresponding entrance point, means controlled by said master control relay upon becoming deenergized for opening said circuit and thereby placing all of the-traffic govern ing means in condition to stop a second vehicle, and directional means controlled by both the traiiic responsive means for any entrance pointin response to said first vehicle leaving said given stretch of track at'th'e corresponding entrance point for again energizing said master control relay for preparing said circuit to again become closed in response to afirst trafiic responsivemeans for any of said entrance points controlled by a second vehicle for placing the corresponding trafiic governing means in condition to direct said second vehicle to enter said given stretch of track.

5. Railway traffic controlling apparatus for controlling movements of railway vehicles onto a given stretch of track which is not equipped with traific responsive means, comprising in combination, tratlic governing means located adjacent each entrance point for said given stretch of track for governing 'trafiic movements onto the given stretch of track at the corresponding entrance point, first trafiic responsive means located in the rear of the trafiic governing means for each of said entrance points,second traffic responsive means located in advance of the trafiic governing means for each of said entrance points, a circuit closed by the said first trafiic responsive means for any entrance point in response to a first vehicle appraoching in the rear of the traffic governing means for the corresponding entrance point for placing the corresponding trafiic governing means in condition to direct the said first vehicle to enter the said given stretch of track, a master control relay which is normally energized but which becomes deenergized by the second trafiic responsive means for any entrance point in response to said first vehicle entering said given stretch of track at the corresponding entrance point, means controlled by said master control relay upon becoming deenergized for opening said circuit and thereby placing the corresponding traffic governing means in condition to stop a second vehicle, first traffic responsive means located adjacent each exit point for said given stretch of track, second tratfic responsive means located between said given stretch of track and the first traflic responsive means for each of said exit points, a tralfic control relay for each of said exit points, means controlled'by the second traffic responsive means for each of said exit points for energizing the corresponding traffic control relay in response to a vehicle leaving the said given stretch of track at the corresponding exit point, means controlled by the first trafiic responsive means for each exit point for then retaining the trafiic control relay for the corresponding exit point energized as long as the second traflic responsive means is controlled by the vehicle leaving at the corresponding exit point, and means'controlled by each of said traific control relays upon becoming energized for efiecting energization of said master control relay when a vehicle leaving said given stretch of track ceases to control the second traific responsive means for the corresponding exit point.

6. Railway traffic controlling apparatus for controlling apparatus for controlling movements of railway vehicles onto a given stretch of track which is not equipped with traific responsive means, comprising in combination, a first and a second track section adjacent each entrance and exit point for said given stretch of track, each said second track section being between the corresponding first track section and said given stretch of track, a track circuit for each of said track sections each including a source of current and a track relay, trafiic governing means for each of said entrance points, a repeater relay for each of said exit points, a control circuit for each of said repeater relays each controlled by front contacts of the track relays for the section for the corresponding exit point, a trafiic control relay for each of said exit points, a pickup circuit for each of said trafiic control relays each controlled by a back contact of the second track section relay and a front contact of the repeater relay for the corresponding exit point, a first stick circuit for each of said traffic control relays each controlled by a back contact of the corresponding second track section relay, a second stick circuit for each of said trafiic control relays each controlled by a back contact of the corresponding repeater relay, 3. master control relay, a stick circuit controlled by a front contact of each of said second track section relays for normally energizing said master control relay, a plurality of pickup circuits for said master control relay one for each of said exit points eachcontrolled by a front contact of each of said track section relays and by a front contact of a corresponding traffic control relay, a control relay for the trafiic governing means for each of said entrance points each energized by a circuit controlled by a front contact of each of the second track section relays and by a front contact of the master control relay and by a back contact of each trafiic control relay and of the first track section relay for the corresponding entrance point, and means controlled by the control relay for the trafiic governing means for each entrance point for controlling the corresponding trafiic governing means to authorize a vehicle to enter the given stretch of track if the control relay is energized and for controlling the corresponding traffic governing means to stop a vehicle from entering said given stretch of track it the control relay is deenergized.

7. Railway traffic controlling apparatus for controlling apparatus for controlling movements of railway vehicles onto a given stretch of track which is not equipped with trafiic responsive means, comprising in combination, a first and a second track section adjacent each entrance and exit point for said given stretch of track, each said second track section being between the corresponding first track section and said given stretch of track, a track circuit for each of said track sections each including a source of current and a track relay, trafiic governing meansfor each of said entrance points, a repeater relay for each of said exit points, a control circuit for each of said repeater relays each controlled by front contacts of the track relays for the sections for the corresponding exit point, a traffic control relay for each of said exit points, a pickup circuit for each of said traific control relays each controlled to energize the corresponding traffic control relay in response to a vehicle entering the second track section for the corresponding exit point when leaving said given stretch of track, stick circuit means for each of said traffic control relays for then retaining the corresponding traffic control relay energized as long as either the second or the first track section for the corresponding exit point is occupied by the vehicle, a master control relay, a stick circuit controlled by front contacts of each of said second track section relays for normally energizing said master control relay, pickup circuit means for said master control relay controlled by a front contact of each of said second track section relays and controlled by said traffic control relays for energizing said master control relay when any one of said trafiic control relays is energized, and means controlled by a front contact of each of said second track section relays and of said master control relay and by a back contact of each of said trafiic control relays for controlling the traffic governing means for any of said entrance points to authorize a vehicle to enter said given stretch of track when the vehicle enters the corresponding first track section.

8. Railway traffic controlling apparatus for controlling movements of switchers onto a given switching area which is not equipped with trafiic responsive means and which has one or more entrance points and has also one or more exit points which may also serve as entrance points for said switchers, the combination comprising, a first and a second track section for each of said points which serves as an entrance point or as an exit point or as both an entrance and an exit point, each said track section being adjacent a corresponding one of said points and between the corresponding first track section and the corre sponding said point, a track circuit for each of said sections each including a source of current and a track relay, a signal for each of said entrance points for governing trafiic movements onto said given switching area, a repeater relay for each of said exit points, an energizing circuit for each of said repeater relays each controlled by front contacts of both track relays for the corresponding exit point, a tratfic control relay for each of said exit points, a pickup circuit and a first stick circuit for each of said trafiic control relays each controlled by a back contact of the second track section relay for the corresponding exit point and the pickup circuit also controlled by a front contact of the corresponding repeater relay, a second stick circuit for each of said traffic control relays each controlled by a back contact of the corresponding repeater relay, a master control relay, a stick circuit and one or more pickup circuits for said master control relay each controlled by a front contact of each of said second track section relays and each pickup circuit also controlled by a front contact of a corresponding traflic control relay, a signal relay for each of said signals, an energizing circuit for each of said signal relays each controlled by front contacts of all of said second track section relays and said master control relay and by back contacts of all said trafiic control relays and of the first track section relay for the corresponding entrance point, and means controlled by each of said signal relays for controlling the corresponding signal to display a proceed or a stop indication according as the corresponding signal relay is energized or deenergized respectively.

9. Railway traffic controlling apparatus for controlling movements of switchers onto a given switching area which is not equipped with traflic responsive means and which has one or more entrance points and has also one or more exit points which may also serve as entrance points for said switchers, the combination comprising, a first and a second track section for each of said points which serves as an entrance point or as an exit point or as both an entrance and an exit point, each said second track section being adjacent a corresponding one of said points and between the corresponding first track section and the corresponding said point, a signal for each of said en trance points for governing traflic movements onto said given switching area, a repeater relay for each of said exit points, an energizing circuit for each of said repeater relays each normally energized but being deenergized in response to either track section for the corresponding exit point being occupied by a railway vehicle, a trafiic control relay for each of said exit points, means controlled by a switcher upon entering a second track section while leaving said given switching area for energizing a corresponding traffic control relay and for then retaining the traffic control relay energized until both track sections for the corresponding exit point are again unoccupied, a master control relay which is normally energized but becomes deenergized in response to any of said second track sections becoming occupied by a switcher, means controlled by any one of said traffic control relays if energized while all of the second track sections are unoccupied for again energizing said master control relay, a signal relay for each of said signals, means for energizing each of said signal control relays in response to a switcher entering the first track section for the corresponding entrance point while all the second track sections are unoccupied and the master control relay is energized and all the traffic control relays are deenergized, and means controlled by each of said signal relays for controlling the corresponding signal to display a proceed or a stop indication according as the corresponding signal relay is energized or deenergized respectively.

References Cited in the file of this patent UNITED STATES PATENTS 

